Dugong Facts

Adults run about 8 to 10 feet and 500 to over 1,000 pounds, with a torpedo-shaped body, paddle-like foreflippers, and no hind limbs. The surest way to tell a dugong from a manatee is the tail: a dugong has a notched, horizontal fluke, a manatee a rounded paddle. Its strongly downturned muzzle is covered in sensitive bristles that find plants in murky water, and dense, heavy bones act as ballast to hold it near the seabed while it grazes. Nostrils on top of the snout seal underwater, so it must surface to breathe. Older males and some females grow projecting upper incisors — small tusks — used in breeding competition. Despite a whale-like look, sirenians are more closely related to elephants and hyraxes; Steller's sea cow, hunted out in the 1700s, was the dugong's nearest relative, leaving Dugong dugon the sole surviving dugongid. See the dugong vs manatee comparison for how the two differ.

Dugongs inhabit shallow tropical and subtropical coast waters across the Indo-Pacific, from East Africa and the Red Sea through South and Southeast Asia to northern Australia, New Caledonia, and Vanuatu. They favour calm bays, reef lagoons, and broad seagrass flats usually less than about 30 feet deep, and — unlike many manatees — they do not enter freshwater rivers, staying tied to marine plant beds. Distribution follows seagrass rather than a continuous coastline: a bay may hold animals while the next shore has none. Some populations travel tens or hundreds of miles chasing forage and warm water; others stay within a small network of bays. Australia holds some of the largest remaining populations, while many Asian and island stocks are now small and scattered.

Dugongs are strict herbivores specialized on seagrass. They crop leafy shoots but often dig into the sediment for nutritious roots and rhizomes, leaving distinct paired furrows across the meadow that show up in aerial surveys. Feeding runs for hours a day because the food is bulky and low in calories, and grit and fibre wear the teeth so hard that dugongs, like manatees, continuously replace their cheek teeth. They tend to select fast-growing, low-fibre, high-nitrogen seagrasses, and moderate grazing can actually stimulate fresh growth — though heavy feeding in a small meadow, especially after a storm or heatwave, can strip it. Healthy seagrass is not just a food source; it is the entire foundation of dugong survival.

Dugongs are usually solitary or travel as loose mother–calf pairs, though animals may gather where food is rich, in fluid herds rather than fixed groups. They communicate with soft chirps and squeaks — most important between a calf and mother in cloudy water — and spend the day feeding, cruising slowly between meadows, and resting near the surface. Cruising speed is modest, but a startled dugong can put on a short burst. Feeding animals surface every few minutes for air; a resting one may stay down longer. Because they must reach the surface to breathe, fast boats crossing feeding grounds can strike them before either side reacts.

Dugongs reproduce slowly. Females often mature in their teens and usually bear a single calf after about 13 to 15 months' gestation, giving birth underwater; the newborn rises at once for air, then nurses on rich milk from teats behind the foreflippers. The calf may depend on its mother for well over a year, riding her slipstream and learning travel corridors, feeding patches, and safe places to surface. Calving intervals commonly span several years, and a dugong that survives boats, nets, and sharks may live for decades — sometimes near 70 years, its age readable in growth layers of the tusks. That long life paired with rare births means populations recover only slowly, and the loss of one breeding female removes many potential future calves.

The dugong is listed as Vulnerable, and many local populations keep declining. The biggest pressure is loss and damage to seagrass from coastal development, dredging, polluted runoff, and destructive fishing; marine heatwaves and severe storms can wipe out meadows across whole bays, and recovery takes years. Boats strike surfacing animals and nets entangle them, and hunting continues in some regions. Because dugongs depend so tightly on coastal plants, the clearest path forward is protecting and restoring connected seagrass meadows and cutting boat and net deaths — through speed zones, modified gear, quick release from entanglement, and watershed management that keeps sediment and nutrients off the coast. The global listing covers the species as a whole; some regional populations are far smaller and more threatened than Australia's large aggregations suggest.

• IUCN Red List of Threatened Species: Dugong dugon
• Australian Government: Dugong
• Save Our Marine Life: Dugongs and seagrass
• National Geographic: Dugong